Flotation cell



...par """x Fil'ed oct. 2s, 1940 INVENTOR.

PAUL L. W/G 70A )777m W l ATTORNEYS,

Augo 25, 1942.

Patented ug. 25, 1942 UNITED STATES PATENT OFFICE FLo'rATIoN CELL Paul L. Wigton, Denver, colo. I Application October 23, 1940, Serial No. 362,397

` (Cilaos- 169) a claims.

This invention relates to improvements `in otation cells for the recovery of valuable minerals from their ores. More particularly, the improvement pertains to one or more cells, which are ordinarily used for a preliminary flotation and separation action prior to the classification and final notation steps. u

As ground ore comes from the grinding mill, it maycontain, in addition to the ordinary sands, relatively large pieces containing highly valuable metal or mineral, or particles'that are too large for flotation. It has been found highly advantageous to effect a preliminary separation between at least some of the notable size particles, the sands, and the unusually large .and/or heavy valuable pieces, before the materialis introduced into the classifier.

One reason why this is desirable is that sands and heavy pieces separated in the classifier are ordinarily returned to the grinder for further reduction, but this regrinding is undesirable since it may make valuable constituents more difficult to recover in a later step of the process. Howtion, the scope of which is, in reality, measured by the appended claims.

In the drawing, reference character 5 de' notes a single flotation cell having a forwardly extending lip 6. over which a rotary skimmer 1 removes the froth in the usual manner.

An impeller 8 is carried at the lower end of a column 9, which in turn is driven through the intermediary of a pulley I0 by means of a prime mover or other source of power not shown.

At a side of the cell 5 is an adjustable over' charge compartment I3, and means such as one or more pipes Il, are provided for introducing an upwardly-directed stream of water under pressure, into the cone I4 for purposes that will be ever, when one or more cells are used between l the grinding mill and the classifier, considerable trouble may be encountered with the heavy sands which are inclined to collect in the bottom of the cell and impede its proper operation.

`Therefore, it is an object of this invention to provide a notation cell of this character that has means for efficiently separating particles that are too large or coarse for ordinary flotation and other heavy pieces from the ground ore.

Another object is the provision in a flotation cell, of asand outlet, whereby sands that would otherwise accumulate to excess in the bottom of the cell, may be passed out of the cell in an un'- usually efficient manner.

Other objects and advantages reside in de-- tails of design and construction which will be more fully disclosed'in the following description and in the drawing wherein like parts have been similarly designated and in which:

Figure 1 is a front elevation, partially in Section, of a flotation cell that embodies the present inventive concept; and

Figure 2 is a sectional plan view taken alon the line 2-2 of Figure 1.

In order to disclose an operative reduction to practice of this invention, the 4accompanying drawings which are made a part hereof, will be hereinafter set forth.

One or more tubes I8 are open at their lower ends within the cell 5 adjacent the impeller 8 and positioned ra'dially outward from the impeller, and these tubes I8 open at their upper ends into the interior of discharge compartment I3 below weir I2 and preferably below discharge I6, but somewhat above cone I4 and hydraulic inlet I1.

Under some circumstances, it may be prefer- I able to position the sand outlet tube or tubes shown in Figure 1`, in-which case the upper end described in some particularity. However, this drawing and description which discloses a typical example, should not be4 construed to exof the tubes I8 or Isa preferably would be positioned higher than shown to maintain somewhat the same relationship with the discharge outlet I6.

Operationl In use, pulp or ground ore from the grinding mill is introduced -into the cell 5 after the usual manner as well understood by those skilled in the art.. As the impeller 8 rotates, froth will be formed which will trap some of the nner mineral particles and this will be skimmed over the lip 6.

Some of the heavier sands and particles will rise in the cell and now over weir I2 into discharge compartment I3, dueto the pumping and agitating action. of the impeller.

-In the discharge compartment I3, which' provides a stilling and settling zone, the larger and heavier pieces will tend to Lfall by gravity into the cone is, particularly pieces which are high in specific gravity.

In order to prevent the cone it from iilling and clogging withtoo much sand and other particles not particularly rich in mineral content, anupward component of movement is introduced in cone I4 by discharging water under pressure through hydraulic pipe 01j pipes l1. This hydraulic action will tend to lift unwanted sands and particles and discharge them through I6, whereas the heavier particles will descend in cone It in spite of the upward inuence o the hydraulic jets, from where they may be removed and recovered through clean-out l5.

As hereinbefore stated, some of the sands, i. e., the coarsely ground particles of ore, will tend to accumulate in the bottom of the cell 5, particularly in the corners thereof, from where the acy cumulation will tend to build inwardly toward the impeller. obviouslyI would -be undesirable and would impede the general function of the cell and its impeller in their aerating, agitating and pumping actions.

The tube or tubes I8 or isa each has its lowerend open adjacent the impeller in a direction to receive some of the sands as thei are rotated with the pulp in the cell due to rotation of the lmpeller. These particles of sand will enter the lower open ends of the tube or tubes it or ia and due to the momentum and centrifugal force acting upon them, they will rise through said tubes and be delivered into discharge compartment i3, Where they will be acted'upon by the upward hydraulic force therein so that their heaviest pieces Will settle to the bottom of cone ill and other particles will pass through discharge IB, which 'ordinarily would be in conductive communication with the classier.

Thus is provided a flotation cell in which a preliminary separation is effected between different particles of ground ore; particularly, the heavy pieces are separated and saved from the deleterious eect of regrinding, and thesands are efficiently conducted from the cell in order to prevent excess accumulation therein.

The weir i2 may be adjusted according to circumstances to maintain the optimum 'depth or head of pulp within the cell 5, and due to the particular combination of the sand outlet tubes i8 Yand 18a and the hydraulic stilling and separating means |3-l4-|5-l6-i1, the pulp or ground ore is passed rapidly through the cell without clogging or interruption of operation. of the cell or its impeller, and at the same time large, heavyand highly mineralized pieces are elciently separated and recovered.

-The denite cooperation between the said outlet and the hydraulic separating and discharge This excess accumulation of sand.

means. effects a new. and highly desirable result in the art of mineral separation. New advantages are gained and none of the ordinary func- It will be understood that the term "pu1p as used herein, refers to ground ore carried in a liquid medium such as water, together with otation reagents that are Well known to those skilled in the flotation art.

Hydraulic jets as indicated at i1, may be one, two or more, and there may be provided one, two or any desired number of tubes l or ida.

The term sands is intended to mean ground ore. Due to the particular combination of ccmponents and their cooperative functions, applicant prefers to call this a hydrocell.

The patentable improvement is thought to be Well' defined in the following claims.

iiow weir, the improvement which comprises a discharge compartment having -a mineral cone at its bottom and having a discharge outlet at itsvside, said compartment being in receiving communication with the overflow Weir, means for introducing an upwardly directed now of uid under pressure into the mineral cone, and a sand relief tube open to the interior of the cell adjacent its bottom and open to the interior. of the discharge compartment above said cone and below said outlet and below saidoverilow weir.

2.*In aotation cell having a closed bottom and inclusive of a rotary .impeller and an overflow weir, the improvement which comprises a discharge compartment having a mineral cone at its bottom and having a discharge outlet. said compartment being in receiving communication with the overflow Weir, means for introducing an upwardly directed flow of fluid under pressure into the mineral cone, and a sand relief tube open to the interior of the cell adjacent its bottom and open to the interior of the discharge compartment above said cone and below said overflow weir.

3. In a dotation' cell inclusive of a rotary impeller andan overow Weir, 'the improvement which comprises a discharge compartment in receiving communication with said lWeir and having a mineral cone at its bottom and having a discharge outlet at its side, means for introducing an upwardly directed flow' of duid under pressure into the mineral cone, and a sand relief tube extending into the interior of the cell and open thereto adjacent the periphery of said impeller inf the zone of centrifugal influence thereof, said sand relief tube being also open to 

